The presence of milky white spots on the leaves of a lemon tree indicates one of several possible fungal diseases, including powdery mildew and various fungal leaf spot diseases. Leaf and fruit production are affected by the presence of powdery mildew or leaf spot diseases, and the overall health of the tree will decline.
Leaf Spot Diseases and Powdery Mildew
Both leaf spot diseases and powdery mildew are caused by fungi. These are spread in a variety of ways, including insects such as aphids that carry diseases with them and transmit them to the lemon tree as they feed on the leaves. Powdery mildew thrives in excessively moist soil and standing water and in warm, humid seasons. Fungal diseases use the tree as a host plant and feed on it to produce spores.
The milky white spots that appear on the leaves of the tree are one of the visible physical symptoms of fungal diseases. The spots are frequently sites of spore production from which the fungus spreads spores to other trees and parts of the garden. As the tree is attacked by fungi, it becomes unable to photosynthesize properly as its leaves are killed. This can lead to weak fruit production and eventually the tree's death.
Care for the lemon tree's growing environment to make fungal diseases less likely. Plant the lemon tree in an area where it receives full, direct sunlight to keep it healthy and reduce weak growth, which is more susceptible to fungal problems. Keep the soil free from standing water, which provides a place for fungi to grow. Pick up and remove any fallen leaves, branches or fruit from around the tree; these act as potential hosts for fungi as they rot.
Fungicides and pruning are essential to controlling the white spots on lemon tree leaves. Pinch off leaves that exhibit the white spots and remove them. Prune branches that show signs of dieback, including dead twigs and premature leaf loss. Apply a fungicide to the tree to help kill off and control the presence of spores on the lemon tree; this keeps the tree healthy and stops the fungi from spreading.
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Lemon Trees with White Spots
Lemons are generally easy to grow and are rarely the victims of diseases, such as those that cause white spots on the...